FlightTaskAutoLine: don't update yaw if waypoints are too close together

src/lib/FlightTasks/tasks/AutoLine/FlightTaskAutoLine.cpp

@@ -56,12 +56,8 @@ void FlightTaskAutoLine::_generateSetpoints()
 void FlightTaskAutoLine::_generateHeadingAlongTrack()
 {
 	Vector2f prev_to_dest = Vector2f(&(_target - _prev_wp)(0));
+	_compute_heading_from_2D_vector(_yaw_setpoint, prev_to_dest);
 
-	if (!_compute_heading_from_2D_vector(_yaw_setpoint, prev_to_dest)) {
-		// heading could not be computed. best we can do is to set heading
-		// to current yaw
-		_yaw_setpoint = _yaw;
-	}
 }
 
 void FlightTaskAutoLine::_generateXYsetpoints()